X-ray diffraction experiments on Ag and Ge in normal and supercooled liquid phase

While there are a lot of experiments to investigate the structure of elements or binary alloys above the melting point, respectively the liquidus, there are only few measurements concerning the metastable state of supercooled liquids of such samples. Investigations on supercooled Ag show, in contrast to measurements on supercooled Ge, a strange temperature dependence of the structure factor S(Q). While cooling down below a certain temperature, that is already smaller than the melting temperature of Ag, the form of the structure factor rapidly changes. In a range of approximately 10 K, first the height of the first maximum doubles and afterwards becomes even smaller than 1 for lower temperatures. On the other hand the height of the second maximum similarly heightens but afterwards lessens only a bit. Further investigations on Cu, which has an electron configuration comparable with Ag, show a likewise behaviour. (C) 1999 Elsevier Science B.V. All rights reserved.